Biology subjects

Cordani, M.

Publications and source records attributed to Cordani, M..

4 recordsLinked to original sources

bioRxiv2026

A treatment-resilient lipid metabolic program drives temozolomide resistance in glioblastoma

Temozolomide (TMZ) resistance remains a major barrier to durable control of glioblastoma (GB). Our previous studies showed that simvastatin can enhance TMZ-induced cell death in non-resistant GB cells by disrupting autophagosome-lysosome fusion and engaging stress-response pathways, whereas established TMZ-resistant cells maintain impaired autophagy flux and remain refractory to TMZ, simvastatin, and their combination. Here, we asked whether this loss of therapeutic responsiveness is accompanied by a treatment-resilient lipid state. Targeted LC-MS quantified 304 lipid species across 25 analytical classes in non-resistant (NR) and TMZ-resistant (R) U251-mKate cells under control, simvastatin (ST), TMZ, and TMZ-ST conditions. Global heatmap, principal-component, volcano, and exploratory PLS-DA analyses demonstrated persistent NR/R lipidomic separation across all four treatment states. Resistant cells recurrently displayed enrichment of lysophospholipids, selected sphingolipids/glycosphingolipids, and cholesteryl esters, with depletion or redistribution of several glycerophospholipid and diacylglycerol pools. A family-resolved analysis across 19 lipid families showed that resistance status was most strongly associated with phosphatidylinositol (PI; PERMANOVA R^2=0.52), phosphatidylglycerol (PG; R^2=0.49), lysophosphatidylcholine (LPC; R^2=0.46), lysophosphatidylethanolamine (LPE; R^2=0.45), ether/plasmalogen phosphatidylcholine (R^2=0.45), and phosphatidylcholine (R^2=0.41). Structure-informed target prediction of discriminant lipids generated pathway hypotheses involving Rap1, PI3K-Akt, phospholipase D, calcium, PPAR, and lipid-metabolic signaling. Transmission electron microscopy showed persistent vesicle-rich, autophagosome-like architecture in resistant cells across treatment conditions, consistent with the previously established late-stage autophagy defect. These data extend the autophagy-cholesterol model of TMZ resistance to a broader membrane-remodeling program and indicate that failure of statin sensitization is associated with coordinated lipid-family remodeling rather than a single lipid species or pathway. The identified lipid families and cholesterol-storage phenotype provide testable vulnerabilities for future functional validation. An exploratory family-level linear SVM analysis provided an orthogonal proof-of-concept: several membrane and storage-lipid families retained complete NR/R separation when an entire treatment was withheld, but these internal results were interpreted as supplementary evidence rather than as a validated classifier.

cancer biology↗

bioRxiv2024

Assessing Autophagy Flux in Glioblastoma Temozolomide Resistant Cells

Autophagy is a critical cellular process involved in the degradation and recycling of cytoplasmic components, playing a dual role in cancer by either promoting cell survival or facilitating cell death. In glioblastoma (GB), autophagy has been implicated in resistance to the chemotherapeutic agent Temozolomide (TMZ). This study presents a novel method to accurately measure autophagy flux in TMZ-resistant glioblastoma cells, combining advanced imaging techniques with biochemical assays. By quantifying key autophagy markers such as LC3-II and SQSTM1, our approach provides detailed insights into the dynamic processes of autophagosome formation and clearance under therapeutic stress. This method not only advances our understanding of autophagy in GB chemoresistance but also has significant implications for the development of autophagy-targeted therapies. The ability to monitor and manipulate autophagy flux in real-time offers a promising avenue for monitoring and understnading TMZ resistance and improving patient outcomes in glioblastoma treatment.

molecular biology↗

bioRxiv2024

Unlocking a New Path: An Autophagometer that Measures Flux Using a Non-Fluorescent Immunohistochemistry Method

Macroautophagy/autophagy, a crucial cellular process, is typically measured using fluorescence-based techniques, which can be costly, complex, and impractical for clinical settings. In this paper, we introduce a novel, cost-effective, non-fluorescent immunohistochemistry (IHC) method for evaluating autophagy flux. This technique, based on antigen-antibody reactions and chromogenic detection, provides clear, quantifiable results under standard light microscopy, eliminating the need for expensive equipment and specialized reagents. Our method simplifies technical requirements, making it accessible to routine clinical laboratories and research settings with limited resources. By comparing our approach with traditional fluorescence methods, we demonstrate its superior effectiveness, cost-efficiency, and applicability to patient samples. This innovative technique has the potential to significantly advance autophagy research and improve clinical diagnostics, offering a practical and robust tool for studying autophagy mechanisms in diseases such as cancer and neurodegenerative disorders. Our non-fluorescent IHC method represents a significant step forward in evaluating autophagy flux, making it more accessible and reliable, with the promise of enhancing our understanding and treatment of autophagy-related diseases.

molecular biology↗

bioRxiv2021

Gasdermin B over-expression arbitrates HER2-targeted therapy resistance by inducing protective autophagy

PurposeGasdermin B (GSDMB) over-expression promotes poor prognosis and aggressive behavior in HER2 breast cancer by increasing cell invasion, metastasis and resistance to therapy. Decoding the molecular mechanism of GSDMB-mediated drug resistance is crucial to identify novel effective targeted treatments for HER2/GSDMB aggressive tumors. Experiment designTo decipher the functional relevance of GSDMB in promoting resistance to HER2-targeted therapies we performed several molecular approaches (immunoblot, qRT-PCR, flow cytometry, immunoprecipitation and confocal microscopy) in different breast and gastric carcinoma cell models. The results were confirmed in Patient Derived Xenografts (PDX) by qRT-PCR and in clinical human cancer samples by immunohistochemistry. Finally, we validated the efficacy of the identified targeted treatment in HER2/GSDMB cancers using two complementary in vivo preclinical models (tumor xenografts in mice and zebrafish). ResultsWe discovered that GSDMB up-regulation renders HER2 breast and gastric cancer cells more resistant to anti-HER2 agents by promoting protective autophagy. Consistent with this, we proved that the combination of lapatinib with the autophagy inhibitor chloroquine increases the therapeutic response specifically in GSDMB-positive tumors in vitro and in vivo using zebrafish and mice preclinical cancer models. Mechanistically, we confirmed that the GSDMB N-terminal domain interacts with the autophagy protein LC3B. Finally, we validated these results in clinical samples of breast and gastric cancers, where GSDMB/LC3B co-expression associates significantly with relapse. ConclusionOur findings uncovered a novel functional link between GSDMB over-expression and LC3B-mediated protective autophagy in response to HER2-targeted therapies and provide a new and accessible therapeutic approach for HER2/GSDMB+ cancers with adverse clinical outcome. TRANSLATIONAL RELEVANCEIdentifying the biomarkers and mechanisms of therapy resistance is a main challenge in current oncology. In this regard, Gasdermin-B (GSDMB) over-expression, which was initially found in >60% HER2 breast cancers, promotes resistance to therapy through an unknown molecular mechanism. In the present work, we revealed for the first time that in HER2 gastric and breast cancers GSDMB mediates innate and acquired resistance to HER2-targeted drugs through the promotion of a pro-survival autophagy mechanism that requires the interaction of GSDMB with LC3B. Accordingly, GSDMB/LC3B co-expression in human breast and gastric cancer clinical samples associates with relapse. To reverse this anti-drug effect, we developed a therapeutic approach based on the combination of the autophagy inhibitor chloroquine with lapatinib that showed significant efficacy both in vitro and in vivo on GSDMB-positive tumors. Our findings provide an accessible (FDA-approved drugs) therapeutic combination to treat effectively HER2/GSDMB over-expressing tumors with poor clinical outcome.

cancer biology↗